Vehicle security systems are commonly used to protect against vehicle theft, as well as damage to the vehicle or theft of property from within the vehicle. Traditional vehicle security systems may provide for audible/visual alerts, disabling of the vehicle, and/or other operations upon the detection of a threat. Other vehicle functions are sometimes incorporated within a vehicle security system, or as a stand alone system. One such function is remote keyless entry (RKE), which allows a user to unlock one or more vehicle doors from a wireless transmitter (e.g., a key fob), for example. Another function is remote starting, which allows a vehicle engine to be remotely started in a similar manner.
Various approaches have been used to extend the range of wireless transmitters for vehicle security, RKE, and/or remote start systems, such as deploying separate antennas which may be remotely mounted with respect to a main security or remote start system control module. One such configuration is set forth in U.S. Pat. No. 8,031,125 to Rabinovich et al., which is directed to an antenna and splitter for receiving radio a remote keyless entry signals. The antenna system includes a first antenna having a helical shaped portion, and configured to receive signals over a first frequency range. A second antenna is positioned in proximate distance from the first antenna, and is configured to receive signals over a second frequency range. A splitter is be configured for separating signals received from radio and remote keyless entry antennas and may include a first branch including a first filter to filter AM band signals from communications signals received from an antenna, a second branch including a second filter to filter FM band signals from communications signals received from the antenna, a third branch including a third filter to filter remote keyless entry signals from communications signals received from the antenna, and an amplifier to amplify the remote keyless entry signals. The antenna may be a whip antenna or roof antenna.
The assignee of the present invention offers vehicle security and remote start systems, such as, for example, the Prestige Model APS-787E, that has improved user range due to its mounting of the antenna adjacent the windshield area of the vehicle. The main control unit of the system is positioned beneath the dashboard area, and a shock sensor may be coupled via a short wiring harness, to the main control unit. Accordingly, the shock sensor is thus typically positioned beneath the dashboard, and may be subject to unintentional triggering due to improper mounting or positioning, for example.